In the distant past, parliament would meet when the monarch wished it. But the UK constitution has moved on from those days – at least in that the Queen exercises her power to prorogue parliament only on government advice. But events of the past few weeks have prompted questions about whether the prime minister can seek to suspend parliament at will, for any reason, and for any duration.

Boris Johnson’s government has suspended parliament for five weeks in the run up to the Brexit deadline of October 31. The suspension is being challenged in courts across the UK. Cases have been brought in England and Wales, Scotland and Northern Ireland, with judges asked to decide whether or not the government’s advice to the Queen on prorogation was lawful.

The opening question is whether there are any legal standards applying to this situation in the first place. The challengers have insisted that there are – that the power of prorogation can only be used for certain lawful or “proper” purposes. They claim the government broke the law because rather than using prorogation simply to start a new parliamentary session – a proper purpose – it was really seeking to hinder parliamentary scrutiny ahead of Brexit – an improper purpose.

On September 6 the Divisional Court in London dismissed the case. It held that the matter was “non-justiciable” – that is, a political rather than a legal matter and therefore not a question for the courts. This view was shared by the Belfast High Court.

However, Scotland’s highest civil court disagreed. On September 11 the Court of Session in Edinburgh decided that the power to prorogue parliament was indeed subject to legal rules – namely, it must be used for lawful or proper purposes, as with any other governmental power. It then went on to find that the government broke the law by acting for the improper purpose of “stymying parliament” ahead of Brexit.

Differing judgements

It is striking that courts in different parts of the UK have reached different judgements on the same question. They are split about whether prorogation is a purely political question that judges have no business answering, or whether there are legal rules governing prorogation that judges can enforce.

This spotlights an old and deep problem: whether and how far government conduct is subject to judicial monitoring. It is a problem that the courts face daily, in both humdrum and high-profile cases.

The Divisional Court in London was particularly forceful in insisting that any advice to the Queen about prorogation was “inherently political in nature”. In the court’s view, “there are no legal standards against which” such advice can be judged.

This position is problematic, however. If it was true, it would mean that the courts could never be called upon to act in the political sphere, even if a prorogation order were obtained by a future government through coercion, bribery or fraud. That is hard to accept. And once we admit that at least some judicially enforceable standards are in play, the idea that advice on prorogation is wholly out of bounds for the courts quickly falls apart.

It is also important to recognise just how far the Divisional Court went. Remember that Boris Johnson has publicly repeated that the suspension is innocuous, designed only to bring about a new parliamentary session and to allow the new government to set out its legislative agenda in a Queen’s Speech. On the Divisional Court’s reasoning, this sort of dressing up is unnecessary since prorogation can straightforwardly be used for “political advantage”. In other words, if the court is correct, Johnson could have announced that he was suspending parliament because it was an irritant, a distraction, and an unwelcome impediment to his delivery of Brexit – and he would have been well within his rights.

This may be the most striking feature of the Divisional Court’s decision. It suggests that Johnson actually underestimates just how much power he enjoys under the constitution – and that he is publicly far more cautious than he needs to be.

What will the Supreme Court do?

Attention now turns to the UK Supreme Court which meets on September 17. It is being asked to decide which of the earlier rulings in London and Edinburgh is correct.

The Supreme Court has sound legal reasons to disagree with the Divisional Court’s blunt view that the subject-matter is political and the case cannot be heard. But this result won’t be easy to reach. The notion that certain questions are wholly political, and lacking any legal aspects, has a long history in the case law, and courts have sometimes used this device to turn away awkward cases.

We also cannot forget that judges do not operate in a vacuum; they face pressures as with any other institution. The government has already fired some indirect and disquieting warning shots in response to the Edinburgh ruling, implying that the judges were politically biased against the government.

If the Supreme Court does agree with the Divisional Court that the question is political rather than legal, it will take the UK constitution into quite peculiar territory. Prime ministers will be the new kings and queens. They will be free to suspend parliament at will, and for as long as they wish, without any judicial interference. Parliament will meet not out of constitutional necessity but in the service of the government’s interests – namely, to pass its legislation and to maintain appearances, rather than to hold it to account.

Still, even in these circumstances all is not lost. Such a verdict would likely focus minds on legislative reform. Just as the power to dissolve parliament is regulated by the Fixed-term Parliaments Act 2011, the power to prorogue parliament can also be tamed by legislation. It only requires political will.

Asif Hameed does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.